ASSESSMENT OF MACROINVERTEBRATE COMMUNITIES IN AN ACID MINE DRAINAGE IMPACTED STREAM IN THE GEORGE S CREEK WATERSHED, ALLEGANY COUNTY, MARYLAND

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1 ASSESSMENT OF MACROINVERTEBRATE COMMUNITIES IN AN ACID MINE DRAINAGE IMPACTED STREAM IN THE GEORGE S CREEK WATERSHED, ALLEGANY COUNTY, MARYLAND JULY 23, 2014

2 ABSTRACT Macroinvertebrates are a diverse group of organisms with varying degrees of tolerance to physical and chemical changes in their environment that are often the result of pollution. For this reason, they are often grouped by such tolerance levels and used as bioindicators to help assess the health of a water-body. The presence of the most pollution-sensitive group in a stream, especially the Orders of Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies), or EPT, typically indicates a healthy or unpolluted waterway. Acid mine drainage (AMD) is a highly toxic form of pollution common to mining regions like Western Maryland. To help remediate the effects of AMD in Matthew Run and Neff Run, located in Allegany County, MD, a steel slag bed was installed; however, a previous study found the slag bed was not raising the ph downstream as desired. The purpose of our study was to collect and analyze macroinvertebrate communities to determine if the steel slag bed was operational. We sampled and identified macroinvertebrates at five sites of varying exposure to acid mine drainage and proximity to the steel slag bed treatment. Visual observations were taken at each site and the water ph, the total dissolved solid (TDS) concentration, and the water temperature was measured. Graphical analysis comparing TDS and %EPT and ph and % EPT was conducted and interpreted. Chi squared analysis was conducted comparing the %EPT collected from Site 1 with that of Sites 4 and 5. Results from Chi squared analysis supported our hypothesis that if the slag bed was operational, the percentage of EPT taxa would be statistically similar between Site 1 (our control) and Site 5, the site furthest downstream from the slag bed treatment. However, additional information revealed that the slag bed on Neff Run is currently not operational. Future studies are recommended to periodically determine if the slag bed is working, as they need regular maintenance to ensure effectiveness. INTRODUCTION 1

3 Water is the most important requirement for all life on Earth. All organisms need water to survive and are primarily composed of water. Freshwater is a very limited resource and must be carefully regulated; however, various factors, both natural and manmade, endanger this essential resource. Pollution of water is a serious problem worldwide. Issues range from small point source contaminations, such as gasoline dripping out of a gas tank, to widespread, even landscape level, contaminations. An example of widespread manmade pollution is acid mine drainage. Acid mine drainage, also known as abandoned mine drainage, is a major environmental concern in states where mining is common such as West Virginia, Ohio, Tennessee, Pennsylvania, and western Maryland. Acid mine drainage, or AMD, results from a chemical reaction between air and water with waste rocks such as pyrite. When coal is removed, unwanted materials containing pyrite are cast aside and left exposed to air and water. The increased surface area of such materials provides more space for reaction, producing sulfuric acid (Skousen, J., Hilton, T., & Faulkner, B., n.d.). AMD is corrosive because of its low ph, or acidity, which causes leaching of heavy metals, such as iron, aluminum, and manganese, from rocks into the water. This can increase both the total dissolved solids (TDS) and the suspended solid levels in the water (WPCMAR, 2010). Some of these dissolved solids may precipitate, or fall out, as the ph of AMD-impacted water rises. For instance, when the ph reaches a level of 3, dissolved iron is becomes insoluble and precipitates, rusting the rocks at the bottom and covering the streambed substrates. This discoloration, known as Yellow-boy, is an orange or yellow rust color and is a major characteristic of acid mine drainage ( Acid Mine Drainage: Chemistry, n.d.). Underground mining methods such as drift, slope, and shaft mining and surface mining methods such as mountain top, contour, highway, and area mining are types of mining which can lead to acid mine drainage. This can especially become a problem when waste material and mines are not properly handled and closed. Before 1977, mine owners were not held accountable for their mines and could leave them in any condition when mining was finished. However, in 1977, the Surface Mining Control and Reclamation Act was passed. This law attempts to limit acid mine drainage and other complications that arise as a result of mining by requiring mine operators to meet certain standards of environmental land reclamation (Skousen, J., Hilton, T., & Faulkner, B., n.d). However, many mines from the past are still causing complications. When left untreated, AMD can severely degrade both habitat and water quality, (Callaghan & Earle, Impacts, ) which in turn can leave an environment incapable of supporting life. The suspended solids in AMD-contaminated water renders aquatic plants unable to properly conduct photosynthesis. The increased turbidity of the water blocks sunlight to the plants located at the bottom of the stream, which is vital to their survival. Due to a lack of sunlight, the plants begin to die. The particles suspended in AMD waters also have a negative impact on the survival of small aquatic organisms. The dissolved metals in the AMD, such as iron, aluminum, and manganese, enter the gills of the organisms and limit their ability to breathe. Low ph, which is also associated with AMD, causes an imbalance in the sodium and chloride ions in the blood of aquatic organisms (Callaghan & Earle, ph tolerance, ). 2

4 AMD has serious impacts on benthic macroinvertebrates, aquatic organisms without backbones that are larger than a half-millimeter in size and live in aquatic habitats for at least one stage of their life cycle ( Freshwater, n.d.). Macroinvertebrates are classified into three groups, or taxas, based on their sensitivity to pollutants in their aquatic habitat. The first taxa is the most sensitive to pollution and includes macroinvertebrates such as Ephemeroptera (mayflies), Plecoptera (stoneflies), Trichoptera (caddisflies); together they are known as EPT. As a result, members of the EPT taxa are generally found in healthy streams. The second taxa is moderately tolerant of pollutants in their water, and the organisms are usually found in healthy or fair quality streams ( Stream Macroinvertebrates, 2004). This taxa consists of macroinvertebrates such as alderflies, damselflies, and crayfish. The third and final taxa is most tolerant of water pollutants. The macroinvertebrates in this taxa can be found in healthy, fair, and poor quality streams and include black flies and fishfly larvae. The structure of macroinvertebrate communities within a stream can provide great insight into the physical and chemical conditions of a stream. For example, streams dominated by group three taxa, pollution tolerant organisms, are likely affected by some form of water pollution (Callaghan & Earle, Effects, ). In contrast, healthy streams are typically characterized by the presence of organisms from each of the three pollution tolerance groups and at least a fair number of EPT. There are a few methods used to treat the negative effects of AMD in water sources. One of these methods is the implementation of a steel slag bed. Essentially, a mass of alkaline materials containing calcium alumino-silicate oxides is buried near a stream impacted by AMD (Skousen, J.S. & Ziemkiewicz, P.Z., n.d.). Water from unimpacted, nearby sources is diverted to run through the slag bed, hopefully dissolving the alkaline minerals and carrying them into the impacted stream. This helps to neutralize the acid in AMD-impacted streams and raise the ph to a more circumneutral level, though they do not treat the high level of dissolved solids in AMD-impacted streams. In the 1990s, this method was put into place at George s Creek Watershed in Allegany County, MD. George s Creek Watershed is a large watershed that makes up sixty-seven percent of Allegany County, Maryland. In the 1990s, the Environmental Protection Agency listed George s Creek as an impaired stream. Acid mine drainage was identified as a primary pollutant, entering the stream system in Matthew Run and continuing downstream into Neff Run. In 1999, a two-phase restoration plan entitled the Neff Run Watershed Restoration Plan was implemented and included the installation of a steel slag bed just before Matthew Run joins Neff Run (Environmental Protection Agency, 2005). For our study, we collected macroinvertebrate samples from five sites of varying exposure to AMD along Neff Run and Matthew Run in Allegany County, Maryland. The first site was located upstream from where AMD entered and served as the control site. Site 2 was located directly after the AMD entered the stream, and Sites 3, 4, and 5 were all downstream from the Maryland Bureau of Mines-implemented steel slag bed. Sites 1, 2, and 3 are located on Matthew Run, and Sites 4 and 5 are located downstream from the confluence of Matthew Run with Neff Run. 3

5 The purpose of our study was to collect and analyze macroinvertebrate communities to determine if the steel slag bed was successfully treating the water affected by AMD in Neff Run and Matthew Run. We chose to sample macroinvertebrates because they have various tolerance levels to pollution and are sedentary and cannot easily escape the effects of pollution in the water. Therefore, they provide accurate insight into the quality of the water in streams ( Freshwater, n.d.). We hypothesized that if the steel slag bed is treating the effects of AMD input at Site 2, then we expect the percentage of EPT taxa to have no statistical difference between Site 1 and Site 5. The null hypothesis for our project was that we would observe no difference in the percentage of EPT taxa in macroinvertebrate communities between Site 1 and all the other sites. METHODS Sampling occurred on July 9 and 10, 2014 on Neff Run and Matthew Run, located in the George s Creek Watershed in Allegany County, MD. Five different sites were sampled in our experiment. Site 1 was the control site and was located on Matthew Run before AMD input. Site 2 was downstream just after the AMD input but before the slag bed. The remaining three sites were downstream of the slag bed. Upon arrival at each site, a 30-meter reach, or stream section, was measured and marked. Visual observations such as weather, shade level of each site, the quality of the riparian zone, and water turbidity were made. The composition of riffles, pools, and runs were observed and used to determine which habitats to sample so that an approximate representation of each reach could be sampled. Ten macroinvertebrate sample sites were then marked within each reach. The embeddedness level, or the degree that rocks and sediments are covered at the bottom of the stream, was assessed using the U.S. EPA Visual Assessment Test numerical score that ranged from twenty to zero. Twenty was considered optimal for aquatic life, and zero was considered poor. Water temperature, ph, and TDS were measured at roughly the 7, 14, and 21-meter marks in each reach. A phep meter by HANNA was used to test the ph of the water, and a TDSTestr1 meter by OAKTON was used to measure the total dissolved solids. Macroinvertebrates were collected using a modified version of the U.S. EPA Multi-habitat method and were collected using D-nets. The macroinvertebrates and sediments from the net were placed into buckets, large debris were removed, and samples were then poured into collection containers. Sites were sampled from downstream to upstream, with the exception of Site 3, which was sampled last due to weather. Within each reach, sites were sampled from downstream to upstream to make sure nothing was disturbed. All five sites had intact riparian zones but varied in other characteristics. Site 1 was mostly shaded and was located in a forest. It also had optimal embeddedness. Four riffles, three pools, and three runs were sampled. Site 1 had low turbidity. Site 2 was mostly shaded, had a clear sign of yellow boy, and had an embeddedness score in the marginal range. In this reach, four riffles, three pools, and three runs were sampled. Site 2 had fairly high turbidity and was not clear. Site 3 was mostly shaded, had signs of yellow boy, and scored in the suboptimal 4

6 embeddedness range. Two riffles, four pools, and four runs were sampled. The turbidity in Site 3 was low. Site 4 was partially shaded, had low turbidity, and had a small amount of yellow boy with suboptimal embeddedness. Three riffles and seven runs were sampled. Site 5 was partially shaded, had suboptimal embeddedness, and had low turbidity. Four riffles, one pool, and five runs were sampled at Site 5. The collected macroinvertebrates were taken back to the lab and refrigerated until identification on July 11, Droppers, tweezers, and spoons were used to separate macroinvertebrates from debris. The Stroud Water Research Center Macroinvertebrate Identification cards, microscopes, and internet resources were used to identify organisms to Order and family when possible. Special attention was paid to the macroinvertebrates EPT taxa groups. The total number of macroinvertebrates collected at each site and the number of EPT found at each site were recorded. The number of macroinvertebrates from each pollution tolerance group was also recorded for future analysis. To determine the percentage of EPT, the total number of EPT taxa collected at each site was taken over the total amount of macroinvertebrates at each site. Chi Squared analysis was conducted comparing the percentage of EPT of Site 1 to Site 4 and Site 1 to Site 5. The ph, temperature, and TDS were analyzed by calculating the average of the three samples that were taken. Data was also graphically analyzed. RESULTS Water chemistry results varied at the sites (Table 1). The average ph at Site 4 (ph=8.8) was had the highest ph of all sites tested. Site 3 had the lowest ph of all the sites (ph=4.430, and Site 1, our control site, was neutral (ph=7.00). Sites 2 and 3 had much higher TDS values than all the other sites, 590 and ppm respectively, and Site 1 had the lowest TDS level, 96.7 ppm. Site 2 had the lowest temperature (16.2 C), and temperatures increased as we moved downstream to a maximum of 20.3 C at Site 5. Table 1.The ph, TDs and Temperature averages for study sites. Sites Average ph Average TDS in ppm Average Temperature in C Site Site Site Site Site

7 Site 2 had the lowest number of macroinvertebrates (n=2) and Site 4 had the most macroinvertebrates (n=121). Site 2 had the lowest percentage of EPT (0%) and Site 5 had the highest percentage of EPT (73.02%) (Table 2). Table 2. Macroinvertebrate species found at each site. Taxon Site 1 Site 2 Site 3 Site 4 Site 5 Ephemeroptera (mayflies) Plecoptera (stoneflies) Trichoptera (caddisflies) Anisoptera (dragonflies) 3 1 Zygoptera (damselflies) 3 Sialidae (alderflies) 1 Coleoptera (beetles) Chironomidae (midges) Tipulidae (crane flies) Isopoda (aquatic 3 1 sowbugs) Decapoda (crayfish) Oligochaeta (aquatic 2 2 worms) Total Percent EPT 69.56% 0% 11.11% 25.62% 73.02% Figure 1 shows the distribution of tolerance groups found at each. The macroinvertebrate taxas in yellow represent the most sensitive tolerance level, the red represent the moderate tolerance level, and the green represent the most tolerant macroinvertebrate taxas. Sites 1, 4, and 5 have all tolerance groups present. Sites 1 and 5 also have macroinvertebrates in sensitive tolerance levels making up the majority of the macroinvertebrates collected at these sites. Sites 2 and 3 had the lowest variation in tolerance groups. 6

8 Percentage of Tolerance Groups 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Percentage of Pollution Tolerant Macroinvertebrate Groups at Each Site Site 1 Site 2 Site 3 Site 4 Site 5 Sites Group 1 (least tolerant) Group 2 (tolerant) Group 3 (most tolerant) Fig. 1. The percentage of macroinvertebrate tolerance groups at each site The Chi Squared Analysis determined that there was not a statistical difference between the percentage of EPT between Site 1 and Site 5 (x 2 = 0.36; n=2); however, there was a statistical difference in percentage of EPT between Sites1 and 4 (x 2 = ; n=2). Sites 2 and 3 could not be statistically analyzed due to low sample size. DISCUSSION AND CONCLUSIONS There was no significant difference in the percentage of EPT between Site 1 and Site 5. The difference between Site 1 and Site 4 was statistically significant. Therefore, we reject our null hypothesis which stated that we will observe no difference in the percentage of EPT taxa in macroinvertebrate communities between Site 1 and all the other sites. We accept our alternate hypothesis which stated that if the steel slag bed is treating the effects of AMD input at Site 2, then we expect the percentage of EPT taxa to have no statistical difference between Site 1 and Site 5. The presence and absence of certain tolerance groups at each study site followed the predicted trends. The community structure at Site 1 was expected to include all three tolerance groups with a large number of macroinvertebrates in the EPT taxa (Figure 1). Our data supported this expectation. Site 2 was expected to have the lowest amount of diversity and few, if any members of the EPT taxa. This expectation was also supported by our data. There was only one taxa represented in the data collected at Site 2, and no macroinvertebrates from the EPT taxa were collected. 7

9 Average TDS in ppm Percent EPT Our results showed that Sites 2 and 3 had the highest TDS levels out of all sites tested (Table 1). These high TDS levels may be related to the location of these sites. Sites 2 and 3 were the closest to the AMD input. Site 2 was directly after the input of AMD and received no treatment from the steel slag bed. Consequently, it would be the most impacted by AMD. Site 3 was directly after the steel slag bed and may not have had enough distance for the water to receive proper treatment from the slag bed. Predictably, Site 1 had the lowest levels of TDS, as it was before the AMD input location. Therefore, it was not exposed to the acidic water and increased dissolved solids that are a component of AMD. There appears to be a strong relationship between TDS levels and the percentage of EPT at each site. The sites with the lowest TDS levels had the largest percentage of EPT (Fig. 2). This could be a result of the negative impact that dissolved solids have on aquatic organisms. Solids in the water can block the gills of aquatic organisms and obstruct their breathing. Macroinvertebrates in the EPT taxa are especially sensitive to this characteristic of AMD. Sites 4 and 5 had similar TDS levels, however, Site 5 contained a noticeably larger amount of macroinvertebrates in the EPT taxa. This difference could be a result of other factors such as land use around the sites, additional pollution sources in the area, and the distance from the slag bed Average TDS and Percentage of EPT Taxa at Each Study Site Site 1 Site 2 Site 3 Site 4 Site 5 Sites Average TDS in ppm Fig. 2. The average TDS and percentage of EPT at each study site The ph data appears to show no relationship to the percentage of EPT taxa (Figure 3). The ph levels did not appear to follow any noticeable trend or pattern. Site 2 was expected to have the lowest and most acidic average ph of all five sites due to its proximity to the AMD input; however, the average ph at Site 2 was much higher than anticipated and came close to neutral. 8

10 Average ph Percent EPT Average ph and Percentage of EPT Taxa at Each Study 10 Site Site 1 Average ph Site 2 Site 3 Percent EPT Sites Site 4 Site 5 Fig. 3. The average ph and percentage of EPT at each study site According to the Maryland Bureau of Mines, the steel slag bed is currently not functioning. There is no basic output flowing to the site from the slag bed. This could be due to a blockage of the intake pipes with leaves and gravel or from a lack of maintenance on the slag bed. Therefore other factors are influencing the ph of our sites. The ph at our sites could have been impacted by the high amount of precipitation in the George s Creek Watershed during the first half of Higher flows dilute the ph of the stream water. Rain which generally has a ph just below neutral could have raised the ph of the water at Site 2 (Table 1). Site 2 had a near neutral ph of 6.2. The 2010 study (Beckman, J., et al. 2010) found ph values below 5 for this site. Site 4 had a much higher ph than expected (ph = 8.8). The location of this site may have influenced the ph. Site 4 was located downstream of a large farm. It is possible that agricultural activities near Site 4 are increasing the ph. One limitation of our study was the size of our reaches. Ideally, a 100-meter reach would be sampled, as suggested by the EPA Multi-habitat method. Another limitation is that we were unable collect all samples on the same day, which would help minimize variables such as changes in weather. Another improvement would be to sample macroinvertebrates during the Spring or Fall, as recommended by numerous sources. This recommendation is based on the timing of many macroinvertebrate life cycles. In light of our limitations, future studies should sample from a larger reach section and should ideally do so in the Spring or Fall when the highest numbers of EPT are present. A day should be set aside for testing so there is enough to time sample all sites, reducing additional variables. Future studies may also want to study the functionality of the steel slag bed and how macroinvertebrates are impact by changes in basic inputs from this slag bed. Based on the results of this study, we determined that the effects of acid mine drainage were being remediated downstream from the slag bed in Neff Run; however factors influencing our sites still require future investigation. 9

11 REFERENCES CITED Acid Mine Drainage: Chemistry. (n.d.) Retrieved from Beckman, J. et al. (2010) Effectiveness of Slag Beds in the Treatment of Acid Mine Drainage. Retrieved from Callaghan, T. & Earle, J. ( ). Effects of Mine Drainage on Macroinvertebrates and Fish. Retrieved from Callaghan, T. & Earle, J. ( ). Impacts of Mine Drainage on Aquatic Life, Water Uses, and Man-Made Structures. Retrieved from Callaghan, T. & Earle, J. ( ). Organisms and ph Tolerance. Retrieved from Environmental Protection Agency. (2005). Collaborative Planning Leads to Community-wide Solutions. Retrieved from Freshwater Benthic Macroinvertebrates: Useful Indicators of Water Quality. (n.d.). Retrieved from Skousen, J., Hilton, T., & Faulkner, B. (n.d.). Overview of Acid Mine Drainage Treatment With Chemicals. Retrieved from Skousen, J.S.& Ziemkiewicz, P.Z. (n.d.). The Use of Steel Slag in Acid Mine Drainage Treatment and Control. Retrieved from Stream Macroinvertebrates. (2004). Retrieved from WPCMAR. (2010). Abandoned Mine Drainage: An Epic Tale. United States. Western Pennsylvania Coalition for Abandoned Mine Reclamation. 10